The proposed program of research will prospectively evaluate the adequacy of the stimulus-persistence model in accounting for age changes in temporal resolution. In addition, it will attempt to conceptually relate the stimulus-persistence model to temporal resolution techniques and hypotheses which have been offered in the non-gerontological sensory-perceptual literature. Relatedly, it will attempt to utilize developmental methodology to examine the validity of such techniqes and hypotheses, most notably so-called "direct" measures of visual persistence and the perceptual-moment hypothesis. In addition, it will attempt to identify the determinant stimulus conditions for age changes in stimulus persistence and also the central versus peripheral locus of such a change.